Announce: category-extras 0.1

Dan Doel <dan.doel <at> gmail.com>
2008-03-01 03:26:38 GMT

Hello everyone,
While fooling about with generalized tries a night or two ago, I found myself
once again interacting with fixed points of shape functors and the like, and
so decided it was time to finish cabalizing David Menendez' excellent
category theory inspired modules.[1]
So, it is my pleasure to announce version 0.1 of category-extras. This is an
initial import of the code, with only what work it took to get things
compiling properly. As such, some of the documentation is a bit scanty, and
there is some overlap with other packages (notably, TypeCompose, off the top
of my head), but I hope to rectify that later.
Notable bits include:
* Control.Comonad
* Control.Comonad.Context -- the state-in-context monad
* Control.Functor.Adjunction
-- a class for adjoint functors, and their associated (co)monads
* Control.Recursion
-- Various generalized recursion operators (cata/zygo/histo/apomorphisms)
-- A class for associating fixpoint data types to their shape functors
Also included are some Data.* modules with some comonadic data types (infinite
trees and streams, for instance), but they are in the
as-yet-poorly-documented section of the package.
Haddock 2.0 is required to build what documentation there is for
Control.Functor.Transform, as it uses type operators. However, the rest
should be compatible with earlier versions of haddock. Some modules are

ICFP08 Final CFP

Final Call for Papers
ICFP 2008: International Conference on Functional Programming
Victoria, BC, Canada, 22-24 September 2008
http://www.icfpconference.org/icfp2008
Submission deadline: 2 April 2008
ICFP 2008 seeks original papers on the art and science of functional
programming. Submissions are invited on all topics from principles to
practice, from foundations to features, from abstraction to
application. The scope includes all languages that encourage
functional programming, including both purely applicative and
imperative languages, as well as languages with objects and
concurrency. Particular topics of interest include
* Applications and Domain-Specific Languages
* Foundations
* Design
* Implementation
* Transformation and Analysis
* Software-development Techniques
* Functional Pearls
* Practice and Experience
Important Dates (at 09:00 Apia time, UTC-11)
~~~~~~~~~~~~~~~
Submission: 2 April 2008
Author response: 21 May 2008
Notification: 16 June 2008
Final papers due: 7 July 2008
Call for Papers (full text)

ANN: Takusen 0.8

Alistair Bayley <alistair <at> abayley.org>
2008-03-05 09:24:09 GMT

Oleg and I are pleased to announce the release of Takusen 0.8.
(Don Stewart did an interim 0.7 release for us a few weeks ago,
and added us to Hackage. This release is a tidy-up of some loose
ends, and some bug fixes. Hence, I've summarise the changes
since the 0.6 release.)
Changes since 0.6:
- ODBC support. This still has a few gaps (and probably bugs and rough edges)
but should be fairly usable.
- support for reusable/persistent sessions, so you can hang onto
the connection object between invocations of withSession
(this was in release 0.6 but omitted from the release notes).
- improvements to the Cabal Setup scripts, which should give
better experiences for ghc-6.4, ghc-6.6, and ghc-6.8.
The (eventual) 1.4 release of Cabal should be able to build our
haddock docs, too.
- improved UTF8 decoder (marshals directly from buffer).
The release bundle:
http://hackage.haskell.org/packages/archive/Takusen/0.8/Takusen-0.8.tar.gz
The latest code:
darcs get http://darcs.haskell.org/takusen
Docs:
http://darcs.haskell.org/takusen/doc/html/index.html

ANN: Parsec 3.0.0

Derek Elkins <derek.a.elkins <at> gmail.com>
2008-03-06 06:58:56 GMT

This is a first release of the Parsec 3, the Google Summer of Code of
Paolo Martini.
The main changes are:
* The Parser monad has been generalized into a ParserT monad
transformer.
* The parsers have been generalized to work over a stream of any
type, in particular, with byte strings.
* There is Haddock documentation for almost all functions in the
Text.Parsec tree.
* The Parser monad now has Applicative/Alternative instances
* A "compatibility" Text.ParserCombinators.Parsec tree for the old
Parsec. It's not perfect, but it should work with most Parsec 2
code.
This package should be installable from with cabal install or with the
standard cabal invocations.
Cabal release:
http://hackage.haskell.org/cgi-bin/hackage-scripts/package/parsec-3.0.0
The darcs repository is at:
http://code.haskell.org/parsec3
Note that this package is a new version of the parsec package and so
will hide the old parsec-2.1.0.0 package.

Google summer of code

Reply-To: haskell-cafe <at> haskell.org
Google Summer of Code
As many of you will already know, Google is running its "Summer of Code"
project again this year, and haskell.org is once again going to apply to
be a mentoring organisation. Are you a student who would like to earn
money for hacking in Haskell? Or are you a non-student who has a cool
idea for a coding project but no time to do it yourself?
Well, our wiki to gather ideas is now up-and-running again:
http://hackage.haskell.org/trac/summer-of-code
Add yourself to the list of interested people! Especially potential
mentors.
There are some ideas still there from last year, in the trac tickets.
However, due to the amount of spam accumulating there, I suggest that
this year, we use the haskell-cafe email list as a place to put out
project ideas, solicit feedback on them, and look for interested people.
Prefix any message subject line with with [GSoC] to help others find
them.
Google will start accepting student applications on 24th March, but now
is the time to start gathering thoughts and matching up interesting
ideas with interested people.
The official timeline is as follows:
March 12: Mentoring organization application deadline

Local Haskell meeting + Hackathon, Leipzig, Germany, April 18-20

HaL 3, the third Haskell in Leipzig meeting,
will take place on Friday, April 18, 2008 (late afternoon).
Tentative program:
- Janis Voigtlaender: Theorems for free
- Jürgen Nicklisch-Franken: The Making of Leksah
http://code.haskell.org/leksah
The HaL meeting will be combined with a Hackathon weekend (19.-20.4.),
where we want to work on the Haskell Eclipse plugin
(refactoring, IDE integration, ...),
see http://leiffrenzel.de/eclipse/wiki/doku.php
For more details and registration, see http://iba-cg.de/hal3.html.
Note: For HaL, we could use one more talk (30 min, in German or English)
so if you have something, please tell us. Preference will be given
to reports on Haskell in (business) applications.
Alf Richter (iba Consulting) and Johannes Waldmann (HTWK Leipzig)

Haskell Weekly News: March 09, 2008

Don Stewart <dons <at> galois.com>
2008-03-09 21:33:26 GMT

---------------------------------------------------------------------------
Haskell Weekly News
http://sequence.complete.org/hwn/20080309
Issue 71 - March 09, 2008
---------------------------------------------------------------------------
Welcome to issue 71 of HWN, a newsletter covering developments in the
[1]Haskell community.
Another busy week on the Haskell library front, with around 100 new
and updated libraries and tools on Hackage.
1. http://haskell.org/
Announcements
Google Summer of Code. Malcolm Wallace [2]announced Google is running
its 'Summer of Code' project again this year, and Haskell.org is once
again going to apply to be a mentoring organisation. If you're
interested in earning money to hack on Haskell, and helping out the
community, [3]take a look at the wiki.
2. http://article.gmane.org/gmane.comp.lang.haskell.cafe/37273
3. http://hackage.haskell.org/trac/summer-of-code
Haskell in the browser. Dimitry Golubovsky [4]announced that the YHC
JavaScript backend is now in alpha testing, and is open to
experimentation for those wanting to write Haskell directly for the
browser